Cold hardiness & minimum temperature

Is Catnip (Nepeta cataria)cold hardy? Hardiness zone & min temp

Also called catmint (common), catswort.

About Catnip

Nepeta cataria · also called catmint (common), catswort · herb

Catnip is a hardy mint-family perennial famous for its stimulating effect on cats — about 70% of cats respond to nepetalactone in the leaves. Easy in any sunny well-drained spot. Pet-safe and indeed pet-stimulating; safe in any amount for cats and dogs.

Catnip (Nepeta cataria, Lamiaceae) is a vigorous, somewhat weedy perennial native to Eurasia; its foliage contains nepetalactone, the compound that triggers euphoria in many cats and repels some insects.

Hardy roughly USDA zones 3-9; shear flower spikes after the first bloom to encourage rebloom and curb heavy self-seeding.

Cold limit: USDA 3-9 · RHS H7 (15-26°C)

Sources: hort.extension.wisc.edu, plants.ces.ncsu.edu, missouribotanicalgarden.org

What catnip's hardiness rating actually means

Yes — catnip is genuinely cold hardy. Rated RHS H7 and USDA 3-9, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H7 means: Hardy in the severest European continental winters. On the US scale that maps to USDA 3-9 — the zones where it can be left outdoors year-round.

New to these scales? The USDA hardiness zone map explained covers how the zone numbers work, and you can find your own zone with the zone finder.

Minimum temperature — and what happens below it

Minimum survivable temperature is roughly below about −20 °C. Catnip is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for catnip as it gets too cold:

It tolerates winter lows to about −20 °C once established.
Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root.
First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.

Can catnip go outside or overwinter — and where?

Plant it out within USDA 3-9 and it overwinters with little or no help.
It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy.
The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

Work back from your local frost dates with the frost-date calculator: the last spring frost and first autumn frost are what really decide when catnip can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Catnip hardiness — frequently asked questions

Is catnip cold hardy?

Yes — catnip is genuinely cold hardy. Rated RHS H7 and USDA 3-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Catnip is hardy across USDA 3-9; it belongs in the ground or a frost-proof container, not on a windowsill, and many types actively need a cold winter to perform.

What is the minimum temperature catnip can survive?

Minimum survivable temperature is roughly below about −20 °C. Catnip is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is catnip?

Catnip is rated USDA 3-9 and RHS H7 — Hardy in the severest European continental winters.

Can catnip survive winter outside?

Plant it out within USDA 3-9 and it overwinters with little or no help. It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy. The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

What happens to catnip below its minimum temperature?

It tolerates winter lows to about −20 °C once established. Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root. First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.